Working Principles and Applications of Laser Distance Sensors

With rapid technological advancement, laser distance sensors have become essential high-precision measurement tools. This article introduces the working principles and various application scenarios of laser distance sensors.

Working principles

Laser distance sensors measure distances by using a laser beam and rely on optical properties to compute the distance between the sensor and an object. They calculate distance by measuring the propagation time or angle of the laser.

1. Time-of-flight measurement:

Time-of-flight is one of the most common methods. The sensor emits a short laser pulse and records the time difference between emission and reception. Given the known speed of light, the time difference yields the distance between the sensor and the object.

Process steps:

- Sensor emits a laser pulse.

- The pulse hits the target and reflects back.

- The sensor records emission and reception times.

- Compute pulse travel time using light speed.

- Multiply time by light speed to get object distance.

2. Triangulation:

Triangulation uses geometry: by measuring the incident and reflected beam angles on the sensor, the distance is computed using trigonometry.

Process steps:

- Sensor emits a laser beam.

- The beam reflects from the object.

- Sensor measures incident and reflected angles.

- Compute distance via trigonometric relations.

Some sensors combine methods or use phase/doppler techniques to improve accuracy and stability.

Applications

Laser distance sensors have wide industrial use due to their high precision and responsiveness.

1. Autonomous driving:

They help vehicles detect surrounding distances and shapes, enabling obstacle avoidance.

2. Industrial automation:

Used in robotics, material handling, and assembly lines for precise motion control.

3. 3D scanning:

Used for building measurement, geological survey, and cultural heritage preservation to create accurate 3D models.

4. Security and monitoring:

They monitor positions and distances in security systems for fast alerts and responses.

Laser distance sensors deliver high precision and fast response, making them indispensable. As technology advances, they will find broader applications in fields such as autonomous driving, industrial automation, 3D scanning, and security.

Understanding these principles and applications helps appreciate the value and potential of laser distance sensors.